File

util/random.lua @ 11741:dcf38ac6a38c

net.server: Add a predrain callaback just before writes Allows sneaking in things in the write buffer just before it's sent to the network stack. For example ack requests, compression flushes or other things that make sense to send after stanzas or other things. This ensures any additional trailing data sent is included in the same write, and possibly the same TCP packet. Other methods used such as timers or nextTick might not have the same effect as it depends on scheduling.
author Kim Alvefur <zash@zash.se>
date Mon, 16 Aug 2021 12:34:52 +0200
parent 10016:af8c514e5cf7
child 12446:e54b8a5e35ad
line wrap: on
line source

-- Prosody IM
-- Copyright (C) 2008-2014 Matthew Wild
-- Copyright (C) 2008-2014 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local ok, crand = pcall(require, "util.crand");
if ok then return crand; end

local urandom, urandom_err = io.open("/dev/urandom", "r");

local function bytes(n)
	local data, err = urandom:read(n);
	if not data then
		if err then
			error("Unable to retrieve data from secure random number generator (/dev/urandom): "..tostring(err));
		else
			error("Secure random number generator (/dev/urandom) returned an end-of-file condition");
		end
	end
	return data;
end

if not urandom then
	function bytes()
		error("Unable to obtain a secure random number generator, please see https://prosody.im/doc/random ("..urandom_err..")");
	end
end

return {
	bytes = bytes;
	_source = "/dev/urandom";
};